[A vitamin is] a substance you get sick from if you don't eat it.

Mi è impossibile cingere i fianchi di una ragazza con il mio braccio destro e serrare il suo sorriso nella mia mano sinistra, per poi tentare di studiare i due oggetti separatamente. Allo stesso modo, non ci è possibile separare la vita dalla materia vivente, allo scopo di studiare la sola materia vivente e le sue reazioni. Inevitabilmente, studiando la materia vivente e le sue reazioni, studiamo la vita stessa.
It is impossible to encircle the hips of a girl with my right arm and hold her smile in my left hand, then proceed to study the two items separately. Similarly, we can not separate life from living matter, in order to study only living matter and its reactions. Inevitably, studying living matter and its reactions, we study life itself

A discovery must be, by definition, at variance with existing knowledge. During my lifetime, I made two. Both were rejected offhand by the popes of the field. Had I predicted these discoveries in my applications, and had those authorities been my judges, it is evident what their decisions would have been.

A substance that makes you ill if you don’t eat it.
[His definition of a vitamin.]

All living organisms are but leaves on the same tree of life. The various functions of plants and animals and their specialized organs are manifestations of the same living matter. This adapts itself to different jobs and circumstances, but operates on the same basic principles. Muscle contraction is only one of these adaptations. In principle it would not matter whether we studied nerve, kidney or muscle to understand the basic principles of life. In practice, however, it matters a great deal.

Basic research may seem very expensive. I am a well-paid scientist. My hourly wage is equal to that of a plumber, but sometimes my research remains barren of results for weeks, months or years and my conscience begins to bother me for wasting the taxpayer’s money. But in reviewing my life’s work, I have to think that the expense was not wasted.
Basic research, to which we owe everything, is relatively very cheap when compared with other outlays of modern society. The other day I made a rough calculation which led me to the conclusion that if one were to add up all the money ever spent by man on basic research, one would find it to be just about equal to the money spent by the Pentagon this past year.

Discovery consists of seeing what everybody has seen and thinking what nobody has thought.

I always tried to live up to Leo Szilard's commandment, “don't lie if you don't have to.” I had to. I filled up pages with words and plans I knew I would not follow. When I go home from my laboratory in the late afternoon, I often do not know what I am going to do the next day. I expect to think that up during the night. How could I tell them what I would do a year hence?

I called it ignose, not knowing which carbohydrate it was. This name was turned down by my editor. 'God-nose' was not more successful, so in the end 'hexuronic acid' was agreed upon. To-day the substance is called 'ascorbic acid' and I will use this name.

If any student comes to me and says he wants to be useful to mankind and go into research to alleviate human suffering, I advise him to go into charity instead. Research wants real egotists who seek their own pleasure and satisfaction, but find it in solving the puzzles of nature.

If I go out into nature, into the unknown, to the fringes of knowledge, everything seems mixed up and contradictory, illogical, and incoherent. This is what research does; it smooths out contradictions and makes things simple, logical, and coherent.

If Louis Pasteur were to come out of his grave because he heard that the cure for cancer still had not been found, NIH would tell him, “Of course we'll give you assistance. Now write up exactly what you will be doing during the three years of your grant.” Pasteur would say, “Thank you very much,” and would go back to his grave. Why? Because research means going into the unknown. If you know what you are going to do in science, then you are stupid! This is like telling Michelangelo or Renoir that he must tell you in advance how many reds and how many blues he will buy, and exactly how he will put those colors together.

Knowledge is a sacred cow, and my problem will be how we can milk her while keeping clear of her horns.

Life is water, dancing to the tune of solids.

One death is a tragedy, 100,000 deaths are statistics.

Research is four things: brains with which to think, eyes with which to see, machines with which to measure, and fourth, money.

Research is to see what everybody has seen and think what nobody has thought.

The real scientist … is ready to bear privation and if need be starvation rather than let anyone dictate to him which direction his work must take.

Through the ages, man's main concern was life after death. Today, for the first time, we find we must ask questions about whether there will be life before death.

To regulate something always requires two opposing factors. You cannot regulate by a single factor. To give an example, the traffic in the streets could not be controlled by a green light or a red light alone. It needs a green light and a red light as well. The ratio between retine and promine determines whether there is any motion, any growth, or not. Two different inclinations have to be there in readiness to make the cells proliferate.

We are all but recent leaves on the same old tree of life and if this life has adapted itself to new functions and conditions, it uses the same old basic principles over and over again. There is no real difference between the grass and the man who mows it.

What I want to stress is that the pre-condition of scientific discovery is a society which does not demand “usefulness” from the scientist, but grants him the liberty which he needs for concentration and for the conscientious detailed work without which creation is impossible.

When I received the Nobel Prize, the only big lump sum of money I have ever seen, I had to do something with it. The easiest way to drop this hot potato was to invest it, to buy shares. I knew that World War II was coming and I was afraid that if I had shares which rise in case of war, I would wish for war. So I asked my agent to buy shares which go down in the event of war. This he did. I lost my money and saved my soul.

Why does man behave like perfect idiot? This is the problem I wish to deal with.